Percutaneous myocardial revascularization device and method

ABSTRACT

Devices and methods for creating a series of percutaneous myocardial revascularization (PMR) channels in the heart. One method includes forming a pattern of channels in the myocardium leading from healthy tissue to hibernating tissue. Suitable channel patterns include lines and arrays. One method includes anchoring a radiopaque marker to a position in the ventricle wall, then using fluoroscopy repeatedly to guide positioning of a cutting tip in the formation of multiple channels. Another method uses radiopaque material injected into each channel formed, as a marker. Yet another method utilizes an anchorable, rotatable cutting probe for channel formation about an anchor member, where the cutting probe can vary in radial distance from the anchor. Still another method utilizes a multiple wire radio frequency burning probe, for formation of multiple channels simultaneously. Still another method utilizes liquid nitrogen to cause localized tissue death.

CROSS REFERENCE TO RELATED APPLICATION

[0001] The present application claims the benefit of U.S. ProvisionalPatent Application No. 60/064,169, filed Nov. 4, 1997.

FIELD OF THE INVENTION

[0002] The present application is related to devices and methods forpromoting blood circulation to the heart muscle. Specifically, thepresent invention is related to percutaneous myocardialrevascularization (PMR) devices and methods for forming multiplechannels in the myocardium.

BACKGROUND OF THE INVENTION

[0003] A number of techniques are available for treating cardiovasculardisease such as cardiovascular by-pass surgery, coronary angioplasty,laser angioplasty and atherectomy. These techniques are generallyapplied to by-pass or open lesions in coronary vessels to restore andincrease blood flow to the heart muscle. In some patients, the number oflesions are so great, or the location so remote in the patientvasculature that restoring blood flow to the heart muscle is difficult.Percutaneous myocardial revascularization (PMR) has been developed as analternative to these techniques which are directed at by-passing orremoving lesions.

[0004] Heart muscle may be classified as healthy, hibernating and“dead”. Dead tissue is not dead but is scarred, not contracting, and nolonger capable of contracting even if it were supplied adequately withblood. Hibernating tissue is not contracting muscle tissue but iscapable of contracting, should it be adequately re-supplied with blood.PMR is performed by boring channels directly into the myocardium of theheart.

[0005] PMR was inspired in part by observations that reptilian heartsmuscle is supplied primarily by blood perfusing directly from withinheart chambers to the heart muscle. This contrasts with the human heart,which is supplied by coronary vessels receiving blood from the aorta.Positive results have been demonstrated in some human patients receivingPMR treatments. These results are believed to be caused in part by bloodflowing from within a heart chamber through patent channels formed byPMR to the myocardial tissue. Suitable PMR channels have been burned bylaser, cut by mechanical means, and burned by radio frequency currentdevices. Increased blood flow to the myocardium is also believed to becaused in part by the healing response to wound formation. Specifically,the formation of new blood vessels is believed to occur in response tothe newly created wound.

[0006] What remains to be provided are improved methods and devices forincreasing blood perfusion to the myocardial tissue. What remains to beprovided are methods and devices for increasing blood flow to myocardialtissue through controlled formation of channel patterns in themyocardium.

SUMMARY OF THE INVENTION

[0007] The present invention includes devices and methods for creationof multiple holes in the myocardium of a human heart for percutaneousmyocardial revascularization. A pattern of holes is optimally createdextending from healthy tissue to hibernating tissue, thereby increasingthe supply of blood to hibernating heart muscle tissue. Creating acontrolled pattern of channels rather than simply a plurality ofchannels of unknown location can be accomplished using various methodsand devices. Holes can be considered the space left after a volumetricremoval of material from the heart wall. Channels have a depth greaterthan their width and craters have a width greater than their depth.

[0008] One method includes marking a first location in the heart musclewall with a radiopaque marker, then positioning a radiopaque cutting tiprelative to the radiopaque marker using fluoroscopy and cutting channelsin the myocardium where appropriate. Suitable markers can be secured tothe endocardium mechanically with barbs or pigtails or injected into themyocardium. Suitable channel patterns include lines, arrays, andcircular clusters of channels.

[0009] Another method includes injecting radiopaque material into thenewly formed channels, thereby marking the positions of the channelsalready formed. The radiopaque material should be held in place withpolymeric adhesives for the duration of the treatment. The channelsformed can be viewed under fluoroscopy using this method. The marker canremain throughout the procedure or only long enough to record theposition for mapping.

[0010] Yet another method can be accomplished by providing a myocardialchannel forming device having an anchoring member, a treatment memberwith a cutting tip, means for rotating the cutting member about theanchoring member, and means for controlling the radial displacement ofthe cutting tip from the anchoring member. The anchoring member can beimplanted in a heart chamber wall using a pigtail, and the radial androtational displacement of the cutting tip controlled to sequentiallyform a circular cluster of channels about the anchoring member. Thecircular cluster preferably includes both healthy and hibernating tissueareas, which can be mapped using conventional techniques. A variant ofthis technique utilizes a device having a spline and corresponding starshaft, which restricts the number of possible rotational angles andprovide predictable arc rotations around the spline for the treatmentmember about the anchoring shaft.

[0011] Still another method utilizes a bundle of fibers within a sheathas the cutting device. Preferred fibers are formed of Nitinol wire andcarry radio frequency current to effect burning channels in themyocardium. Optical fibers carrying laser light for burning are used inanother embodiment. The splay of fibers out of the distal end of thesheath can be controlled by controlling the bias of the fibers. The biasof the fibers can be controlled by utilizing shape memory materials,such as Nitinol wire. The splay of fibers can also be controlled bycontrolling the length of fiber exposed at the distal end, bycontrolling the retraction of the sheath over the fibers.

[0012] A variant device utilizes a magnetically responsive anchoringmember, which can be pulled against the heart wall by an externalmagnetic force. The heart wall can have movement lessened during thisprocedure and other procedures generally, by inserting a catheter havinga magnetically responsive distal region into a coronary artery. Forcecan be brought to bear upon the heart wall region having the catheterdisposed within by applying a magnetic force on the catheter. Theapplied force can exert a pulling force on the catheter, reducingmovement of the beating heart wall in that region.

[0013] Another device includes an outer positioning tube having severalside channels in the distal region and means for securing the distalregion against movement within the heart chamber. One securing meansincludes a suction orifice near the distal end supplied with vacuum by avacuum lumen extending the length of the outer tube. Another securingmeans includes a magnetically responsive portion of the outer tube. Thesuction orifice can be secured to the heart chamber wall by applyingvacuum and the magnetically responsive portion can be forced into thechamber wall by applying an external magnet field. The inner tube cancontain an intermediate guide tube and the guide tube can contain aninner PMR cutting wire with a arcuate biased distal region. As thearcuate distal region is moved through the outer tube distal region andover the side channels, the PMR wire distal region can extend through aside channel and to the heart chamber wall. The PMR wire can be movedpast undesired side holes by rotating the wire such that the arcuatewire region is oriented away from the side holes.

[0014] Another device includes a tube-in-a-tube configuration, having anouter tube disposed about an intermediate tube disposed about an innerPMR cutting probe. The inner PMR probe can be preformed to have a distalregion arcuate or angled bias, bent away from the longitudinal axis ofthe probe. The PMR probe distal region can extend through a side channelin the distal region of the intermediate tube and is slidable within theintermediate tube, thereby exposing a varying length of distal PMR probeoutside of the intermediate tube. The intermediate tube is slidablydisposed within the outer tube which has an elongate slot to allowpassage of the PMR probe therethrough. Thus, the radial extent or lengthof extending PMR probe can be varied by sliding the PMR probe within theintermediate and outer tubes, the longitudinal position of the PMR probecan be varied by sliding the intermediate tube within the outer tube,and the rotational position can be varied by rotating the outer tubefrom the proximal end. Varying the amount of a preformed, bent PMR probeextending from the intermediate tube can also change the longitudinalposition of the PMR probe distal end.

[0015] Another device includes an elongate rod having a distal regionsecured to an outer collar, such that the outer collar can be pushed andpulled. The outer collar is slidably disposed over an intermediate tube.An inner PMR cutting probe is slidably disposed within the intermediatetube. The inner PMR probe and intermediate tube together have a distalregion arcuate or bent bias or preform, such that distally advancing theouter collar over the intermediate tube straightens out the intermediatetube and proximally retracting the outer collar allows the arcuate biasor bend to be exhibited in the distal region shape of PMR probe andintermediate tube. The preform can exist in the PMR probe, intermediatetube, or both. The device includes means for anchoring the device to theventricle wall. Circles or arcs of myocardial channels can be formed byrotating the outer tube, extending the inner PMR probe, and varying theamount of arc to form distal of the outer collar.

[0016] Yet another device includes an anchoring member and apositionable cryanoblative treatment tube. The treatment tube can beformed of metal and be either closed or open ended. In use, the deviceis anchored within a heart chamber and a cryogenic substance such aliquid nitrogen delivered through the tube and to the tube distal end.The liquid nitrogen can cause localized tissue death, bringing about thedesired healing response. Still another device includes a plurality ofsplayed, cryanoblative tubes within a sheath. The tubes can be suppliedwith liquid nitrogen, which can be delivered through the tube lumens tothe tube distal ends so as to cause localized myocardial tissue death atmultiple sites substantially simultaneously.

[0017] In yet another embodiment, a catheter assembly is providedincluding a guide wire having a proximal end and a distal end. Anexpandable member, which may be a wire loop, is disposed at the distalend of the guide wire. The expandable member is moveable between a firstposition and a second position. In the first position, the member iscollapsed to move through a lumen of a guide catheter. In a secondposition, the expandable member has a transverse diameter, with respectto the length of the guide wire, greater than the transverse diameter ofthe guide catheter lumen. An elongate catheter having a proximal end anda distal end is disposed on the guide wire. A therapeutic device isconnected to the distal end of the catheter. The therapeutic device canbe a needle, hypotube, electrode or abrasive burr to form holes orcraters in the myocardium of the patient's heart.

BRIEF DESCRIPTION OF THE DRAWINGS

[0018]FIG. 1 is a fragmentary, side, cutaway view of a left ventriclehaving an anchorable, positionable PMR device within;

[0019]FIG. 2 is a fragmentary, side view of the PMR device of FIG. 1,showing anchor and treatment members is phantom within a catheter shaft;

[0020]FIG. 3 is a top view of the PMR catheter and ventricle of FIG. 1,showing a transverse cross-sectional view of the PMR catheter and afragmentary cross-section and projection of the ventricle wall;

[0021]FIG. 4 is a fragmentary, perspective view of a multiple-tip PMRtreatment device according to the present invention;

[0022]FIG. 5 is an end view of the multiple-tip PMR treatment device ofFIG. 4;

[0023]FIG. 6 is a fragmentary, side, cutaway view of a left ventriclehaving a magnetically anchorable, positionable PMR device within;

[0024]FIG. 7 is cutaway, perspective view of a heart having amagnetically positionable PMR cutting tip within the left ventriclewall;

[0025]FIG. 8 is a perspective view of a heart having a magnetic, heartwall stabilizing catheter disposed within the left coronary artery,shown in phantom;

[0026]FIG. 9 is a perspective view of a multiple channel positioningdevice for forming multiple myocardial channels in a ventricle wall,having distal anchoring means and containing a guide catheter containinga PMR cutting wire, both drawn in phantom;

[0027]FIG. 10 is a fragmentary, perspective view of a device related tothe device of FIG. 9, illustrated without distal anchoring means, betterillustrating a shape member within the device;

[0028]FIG. 11 is a perspective view of a tube-in-a-tube positioningdevice for positioning a PMR cutting probe, having an outer tubecontaining an inner tube containing a PMR cutting probe;

[0029]FIG. 12 is a fragmentary, perspective view of a section throughthe PMR probe of FIG. 11, better illustrating the shape member;

[0030]FIG. 13 is a perspective view of an extendable collar device forpositioning a PMR probe, having a slidable collar over an intermediatetube over a PMR cutting probe;

[0031]FIG. 14 is a fragmentary, side, cutaway view of a left ventriclehaving an anchorable, positionable cryanoblative PMR device within;

[0032]FIG. 15 is a fragmentary, perspective view of a multiple-tipcryanoblative PMR treatment device according to the present invention;

[0033]FIG. 16 is a perspective view of yet another embodiment of thedevice in accordance with the present invention;

[0034]FIG. 17 is a view of the device of FIG. 16 in use;

[0035]FIG. 18 is an alternate embodiment of the device of FIG. 16;

[0036]FIG. 19 is an alternate embodiment of the device of FIG. 16; and

[0037]FIG. 20 is an alternate embodiment of the device of FIG. 16.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0038]FIG. 1 illustrates an anchorable percutaneous myocardialrevascularization (PMR) treatment catheter 20 disposed within a leftventricle 34. PMR catheter 20 includes an inner star shaft 24 disposedwithin an outer catheter shaft 22, an anchoring shaft 26 disposed withinstar shaft 24, and a treatment shaft or probe 30 disposed withincatheter shaft 22. Catheter shaft 22 has been cut away proximally inFIG. 1, illustrating inner star shaft 24 within. Anchoring shaft 26 hasan anchor 28 disposed at the distal end. In a preferred embodiment,anchor 28 has a pigtail or corkscrew configuration, capable ofreversibly securing itself to the ventricular wall through rotation ofanchoring shaft 26. One embodiment anchor includes a distal barb,capable of securing itself to the ventricular wall through translationof anchoring shaft 26, not requiring shaft rotation for anchoring. Inanother embodiment, anchoring shaft 26 includes a vacuum lumentherethrough terminating in a distal orifice or suction tip (not shown).Treatment shaft 30 has a distal cutting tip 32, shown embedded within asection of a left ventricular wall 36. The term “cutting” as used hereinincludes penetrating and channel forming by other means.

[0039] Referring now to FIG. 2, PMR catheter 20 is illustrated in moredetail. Anchor shaft 26, extending through outer catheter shaft 22,includes a distal radiopaque marker 38. Treatment shaft 30, extendingthrough catheter tube 22, preferably includes an arcuate, distal region33 and a distal radiopaque marker 40. Radiopaque markers 38 and 40 canaid in determining the positions of the anchoring and treatment shaftsunder fluoroscopy. Suitable radiopaque materials are well known to thoseskilled in the art, including barium, bismuth, tungsten and platinum.Referring now to FIG. 3, PMR catheter 20 is illustrated in a top,cross-sectional view taken through the catheter. In a preferredembodiment, anchoring shaft 26 is contained within an anchor shaft lumen27. Anchor shaft lumen 27 is preferably slidably disposed within aninner shaft such as star shaft 24. Inner shaft 24 preferably has a starshape and is disposed within a star lumen 25 having internal splinescorresponding to the vertices of star shaft 24. Treatment shaft 30 ispreferably slidably disposed within a treatment shaft lumen 31 withinthe wall of PMR outer shaft 22. As illustrated, treatment shaft 30cutting end 32 has formed several channels 42 in the myocardium ofventricular wall 36.

[0040] The use of PMR device 20 may now be discussed, with reference toFIGS. 1, 2 and 3. Several degrees of freedom of movement of cutting tip32 are possible with the present invention. Treatment shaft distalregion 33 is preferably biased to assume a more radially extendedposition when unconstrained by lumen 31. Cutting tip 32 may be seen tohave a radial distance “R” from anchoring shaft 26, as indicated in FIG.2. Holding the axial displacement of anchoring shaft 26 and treatmentshaft 30 fixed while distally, axially sliding catheter outer shaft 22over both shafts 26 and 30 causes more of treatment shaft distal region33 to be drawn into outer shaft 22, thereby decreasing the radialdistance R of cutting tip 32 from anchoring shaft 26. Thus, byproximally fixing the longitudinal positions of anchoring shaft 26 andtreatment shaft 30, and sliding outer shaft 26 over a range of motion, aseries of channels along a line extending radially outward fromanchoring shaft 26 can be created. It will be recognized that, to theextent the inner ventricular wall does not match the arcuate shape oftreatment shaft distal region 33, it may be necessary to adjust thelongitudinal displacement of treatment shaft 30 within outer shaft 22 aswell, to enable cutting tip 32 to reach the endocardium.

[0041] In addition to cutting a series of channels radially outward fromanchoring shaft 26, cutting tip 32 can also describe an arc abouttreatment shaft lumen 31, best visualized with reference to FIG. 3. Byrotating treatment shaft 30 within lumen 31, cutting tip 32 can sweepthrough an arc, cutting a regular series of channels into themyocardium. By varying radial distance R and the rotation of treatmentshaft 30, a regular series of arcs of channels can be formed, with thearcs having increasing radial distance from outer shaft 22.

[0042] Outer shaft 22 can also be rotated relative to anchoring shaft26, thereby enabling the cutting of a regular series of channels in acircle about anchoring shaft 26. In a preferred embodiment, anintermediate star shaft such as shaft 24 is disposed between anchoringshaft 26 and outer shaft 22. Star shaft 24 can serve to restrict therotational positions possible for outer shaft 22 relative to inner,anchoring shaft 26. Outer shaft 22 having internal splines, is notfreely rotatable about the vertices of start shaft 24. In order forouter shaft 22 and carried treatment shaft 30, to be rotated aboutanchor shaft 26, star shaft 24 can be star shaped only is a limiteddistal region, and outer shaft 22 only splined in a limited distalregion. In a preferred embodiment, star shaft 24 and outer shaft 22, ata location proximal of the cross section of FIG. 3, have smooth outerand inner surfaces, respectively. The smooth surfaces allow star shaft24 to be rotated within outer shaft 22 when star shaft 24 has beenretracted proximally into the smooth region. After rotation, star shaft24 can be advanced distally, sliding within a spline of outer shaft 22.The rotation of outer shaft 22 can thus be restricted when desired andenabled when desired. When enabled, rotation of shaft 22 can thus berestricted to a discrete set of rotational angles. Another embodiment ofthe invention dispenses with intermediate, start shaft 24, allowingouter shaft 22 to rotate directly about inner, anchoring shaft 26. Inthis embodiment, the rotation of outer shaft 22 about anchoring shaft 26is not restricted to a set of discrete rotational angles.

[0043] Cutting tip 32 can form a substantially regular pattern ofchannels. Cutting tip 32 preferably is formed of a wire such as Nitinolor elgiloy or stainless steel, and is capable of delivering the radiofrequency current used for cutting channels in the myocardium. Asuitable device for radio frequency cutting is described in co-pendingU.S. patent application Ser. No. 08/810,830, filed Mar. 6, 1997,entitled RADIOFREQUENCY TRANSMYOCARDIAL REVASCULARIZATION APPARATUS ANDMETHOD. By restricting the movement of cutting tip 32 to movementsrelative to anchor tip 28, a more regular pattern of channels can beformed, even with limited fluoroscopic feedback, relative to the patternformed by a cutting tip operating independent of the anchoring tip.

[0044] Referring now to FIG. 4, a multi-fiber treatment probe 50 isillustrated. Treatment probe 50 includes a plurality of wires or opticalfibers 54, having distal cutting tips 56, and enclosed within a sheath52. FIG. 5 illustrates and end view of multi-fiber probe 50, showingdistal cutting tips 56 in the pattern they would have approaching themyocardium. Probe 50 allows a pattern of channels to be formed in themyocardium at the same time, not requiring repeated re-positioning of asingle cutting tip such as cutting tip 32 of FIG. 2. Wires 54 arepreferably formed of Nitinol wire. Use of a bundle of fibers includingmetal wires or optical fibers allows use of RF or laser cutting means,respectively. RF and laser cutting allows use of fibers relatively closetogether, as illustrated in FIG. 5. Mechanical cutting tips, such asthose using rotating cutting blades, can require more space betweencutting tips, not allowing the dense coverage of FIG. 5. In oneembodiment, the cutting tips have an outside diameter “D” and an averageinter-strand distance “I”, as illustrated in FIG. 5, where I is about 2to 3 times the value of D. The pattern of cutting tips can be controlledby utilizing radially outwardly biased cutting tips, which splay outwardas illustrated in FIG. 4. The amount of splay is controlled in oneembodiment by allowing the enclosing sheath to retract, allowing thecutting tips to splay further outward. Sheath 52 can preventuncontrolled flopping of distal cutting tips 56, which can present aproblem when large inter-strand distances are required, as with somemechanical cutting tips. The coverage of the cutting tips in FIG. 5allows creation of a complete pattern of channels in the myocardiumwithout requiring repositioning of the cutting tips.

[0045] In use, probe 50 can be positioned near the ventricle wall regionto be revascularized, and RF current delivered through distal cuttingtips 56. The resulting myocardial channels can be formed substantiallyat the same time, and a similar pattern delivered to an adjacentventricular wall area soon thereafter.

[0046] In another embodiment of the invention, not requiringillustration, a radiopaque marker can be delivered and secured to aposition in the ventricular wall. Suitable radiopaque materials includebarium, bismuth, tungsten and platinum. Markers believed suitableinclude metal markers having barbs or pigtails to securely engage theventricle wall. Other markers, such as radiopaque gels injected into theventricular wall, are suitable provided they stay in place for thelength of the procedure. Such markers are preferably injected fromwithin the ventricle utilizing a catheter. A preferred method utilizesthe cutting tip to first plant or inject a marker, followed by thecutting of a series of channels in the myocardium. By utilizing aradiopaque distal cutting tip and a fixed, implanted radiopaque marker,the relative positions of the two can be viewed fluoroscopically andadjusted fluoroscopically, thereby allowing formation of a controlledpattern of channels. The radiopaque marker provides a reference pointfor forming a pattern of channels in the myocardium.

[0047] In another embodiment of the invention, the cutting tip injectsradiopaque material in conjunction with the cutting of a channel. Inthis embodiment, as each channel is formed, a radiopaque marker is left,creating a pattern of radiopaque markers viewable fluoroscopically. Thepattern of channels formed in the myocardium are thus immediatelyviewable, giving feedback to the treating physician as to the progressand scope of the pattern of channels. Suitable materials for injectioninto the myocardium are preferably biodegradable or absorbable into thebody soon after the procedure, allowing the myocardial channels to beperfused with blood. A device suitable for cutting and injection ofmaterial is described in copending U.S. patent application Ser. No.08/812,425, filed Mar. 16, 1997, entitled TRANSMYOCARDIAL CATHETER ANDMETHOD, herein incorporated by reference.

[0048] Referring now to FIG. 6, left ventricle 34 having a magneticallyanchorable, positionable PMR device 86 device within is illustrated. PMRdevice 86 is similar in some respects to PMR device 20 illustrated inFIG. 1, with device 86 differing primarily at the distal end ofanchoring shaft 26. Anchoring shaft 26 has a magnetically responsiveportion 80 at the anchoring shaft distal end. “Magnetically responsive”as used herein refers to a material capable of being attracted orrepelled by a magnet. Magnetically responsive portion 80 can be used inconjunction with external magnets to position anchoring shaft 26 againstthe ventricle wall. External magnets such as magnet 84 can be disposedexternal to the body, positioned to direct the distal end of anchoringshaft 26 into the center of a target area in the heart. In oneembodiment, the external magnets are rare earth magnets. In anotherembodiment, the external magnets are superconducting magnets. In apreferred embodiment, several magnets 84 are used to direct anchoringshaft 26 into the heart wall.

[0049] In use, magnets 84 can be used in conjunction with axially movinganchoring shaft 26 to plant anchoring shaft 26 in the desired location.Pairs of magnets in all three dimensions may not be required as the goalis to pull the anchoring shaft against a ventricle wall, not necessarilyto suspend it in place using the magnets. The magnets, in conjunctionwith a radiopaque anchoring shaft tip and fluoroscopy, can be used toguide the anchoring shaft into position and maintain position duringtreatment. In the embodiment illustrated, an anchoring spike 82 lies atthe distal end of anchoring shaft 26. Anchoring spike 82, drawn largerin FIG. 6 than in the preferred embodiment, is used to stabilize theposition of the anchoring shaft distal end once the desired position hasbeen reached. Another embodiment terminates anchoring shaft 26 withoutany spike, rather ending with magnet 80. Still another embodimentterminates anchoring shaft 26 with an orifice, such as a suction tip, incommunication with a vacuum lumen within shaft 26, allowing anchoringshaft 26 to be held in place by applying vacuum to the vacuum lumen andorifice, thereby securing the distal tip of shaft 26 with vacuum pullingagainst the heart chamber wall.

[0050] Referring now to FIG. 7, a heart 35 having a PMR catheter 90disposed within. PMR catheter 90 includes a shaft 92, illustratedextending through the aorta and into left ventricle 34. A magneticallyresponse distal portion 94 is located near a distal cutting tip 96 onPMR catheter 90. As illustrated, cutting tip 96 has been guided intoleft ventricular wall 36 and has cut a channel in the wall. Externalmagnets 84 can be used to position cutting tip 96 into the desiredposition with the aid of fluoroscopy. Distal portion 94 is preferablyradiopaque, to aid in guiding cutting tip 96 into position. As PMRcatheter shaft 92 provides some degree of support to cutting tip 96, andas the primary goal is to pull cutting tip 96 into the ventricular wall,pairs of magnets in all three dimensions may not be required. Externalmagnets 84 serve to position cutting tip 96, and, with the assistance ofcatheter shaft 92, can serve to pull cutting tip 96 into the ventricularwall.

[0051] Referring now to FIG. 8, a magnetically responsive catheter 100is illustrated, disposed within heart 35, being extended through aorta102 into a left coronary artery 104. Catheter 100 includes amagnetically responsive distal region 106, which can be attracted byexternal magnets 84. Catheter 100 can be used in conjunction withexternal magnets to stabilize regions of the heart, lessening the amountof wall movement due to the beat of the heart.

[0052] In use, magnetically responsive catheter 100 can be advanced withaid of fluoroscopy through the aorta and into a coronary artery.Catheter distal region 106 preferably includes radiopaque materials toaid positioning under fluoroscopy. Once in position, distal region 106is effectively located in the heart wall. When stabilization is desired,external magnets such as magnet 84 can be positioned near catheterdistal region 106. By exerting a strong pull on distal region 106, themovement of the heart wall in the vicinity of catheter distal region 106can be lessened.

[0053] Stabilization can be used during intravascular PMR procedures,minimally invasive PMR procedures, and heart procedures generally. Whenused during PMR procedures, the stabilization can serve to lessen heartwall movement in the area being cut. When used during other medicalprocedures, the stabilization can serve to minimize heart wall movementin areas being operated on or otherwise treated. When used duringintravascular PMR procedures, a second, PMR catheter should be provided.

[0054] Referring now to FIG. 9, a multiple-channeled PMR positioningdevice or guiding tube 120 is illustrated. Positioning tube 120 includesa distal end 122, a distal region 124, a proximal end 126, a pluralityof channels 138 within distal region 124, and a lumen 128 therethrough.A distal anchoring means 130 is preferably located distal of distalregion 124 and can serve to fix the position of distal end 122 to thewall of the left ventricle or other heart chamber. In one embodiment,anchoring means 130 includes an orifice or suction tip in communicationwith a vacuum lumen 148, such that anchoring means 130 can be held inplace against a heart chamber wall once positioned near the wall. Inanother embodiment, anchoring means 130 includes a magneticallyresponsive material such that an externally applied magnetic field canforce anchoring means 130 into a heart chamber wall. In thismagnetically responsive embodiment, anchoring means 130 can be similarto distal portion 94 illustrated in FIG. 7. In another embodiment, tubedistal region 124 is magnetically responsive and can be similar tomagnetically responsive region 106 illustrated in FIG. 8. Distal tip 122is preferably formed of soft, atraumatic material and distal region 124formed of sufficiently pliable material so as to allow distal region 124to conform to a ventricle wall.

[0055] Disposed within positioning tube 120 is a guide catheter 142extending from positioning tube proximal end 126 to distal region 124.Disposed within guide catheter 142 is a PMR cutting wire 132, proximallyelectrically connected to an RF energy source 136 and terminatingdistally in a cutting tip 33. PMR wire 132 includes a distal arcuate orbent region 144 proximate distal cutting tip 33. Arcuate region 144 canbe bent or arced so as to have a preformed shape or bias to extendlaterally away from the longitudinal axis of the PMR wire. In oneembodiment, PMR wire lies within positioning tube 120 directly, withouta guide catheter. In a preferred embodiment, a guide catheter such asguide catheter 142 is disposed about the PMR wire. PMR wire 132 isslidably disposed within guide catheter 142 and can be rotated byapplying torque to the proximal end.

[0056] In use, positioning tube 120 can be preloaded with guide catheter142 containing PMR wire 132. PMR wire 132 can be retracted such thatarcuate region 144 is retracted either to a position proximal ofchannels 138 or within positioning tube distal region 124 but retractedwithin guide catheter 142. In this retracted position, PMR wire arcuateregion 144 does not extent from channels 138. With PMR wire retracted,positioning tube 120 can be advanced through the vasculature into aheart chamber such as the left ventricle. Positioning tube distal end122 can be advanced down into the ventricle and up a ventricular wall.With distal end 122 in a desired position, anchoring means 130 can beused to anchor distal end 122 to the ventricular wall. In embodimentswhere anchoring means 130 is magnetically responsive or wherepositioning tube distal region 124 is magnetically responsive, anexternal magnetic force can be applied to pull or push anchoring means130 and distal region 124 into the wall. In embodiments where anchoringmeans 130 is a suction tip, vacuum can be applied to the vacuum lumen incommunication with the suction tip.

[0057] With positioning tube distal region 124 in place, guide catheter142 containing PMR wire 132 can be advanced to push tube distal end 122and PMR wire arcuate region 144 distally out of guide catheter 142. PMRwire 132 can be rotated such that cutting tip 33 is oriented towardchannels 138, and guide catheter 142 and PMR wire 132 retracted togetheruntil cutting tip 33 can be pushed out of channel 138. Cutting tip 33can be advanced through channel 138 and a channel cut into themyocardium. In a preferred embodiment, PMR wire 132 has a depth stop 146proximal of arcuate region 144 that limits the length of wire passedthrough channels 138, such that the depth of a PMR formed myocardialchannel is limited. After myocardial channel formation, PMR wire 132 canbe retracted through the channel and the next, more proximal channelentered. In a preferred embodiment, arcuate region 144 is radiopaque anda series of radiopaque marker bands separate channels 138 to aid inpositioning cutting tip 33. In one embodiment, PMR wire 132 can berotated to cut more than one myocardial channel per positioning tubechannel. In this manner, a series of myocardial channels in a regularpattern can be formed over the length of positioning tube distal region124.

[0058] Referring now to FIG. 10, another embodiment positioning tube 160is illustrated. Positioning tube 160 has a shape member 164 which canassist in forming the U-shape of tube 160 illustrated in FIG. 10. In oneembodiment, shape member 164 is formed of a shape memory material suchas Nitinol and embedded within the wall of tube 160 to impart a shape tothe tube once tube 160 is within a ventricle and is no longer asrestrained as when disposed within a blood vessel or guide catheter. Inanother embodiment, shape member 164 is a pull wire slidably disposedwithin a lumen within tube 160 and fixedly attached to a distal portionof the tube as indicated at 166. In this embodiment, shape member 164can be pushed and pulled from a proximal location outside of thepatient's body so as to assist in imparting a shape to tube distalregion 124. In FIG. 10, the distal most portion of tube 160, includinganchoring means 130, has been omitted from the drawing to more clearlyillustrate the distal termination of shape member 164. From inspectionof FIG. 10, it may be seen that, by rotating positioning tube 160 todifferent anchoring positions, and by advancing PMR wire 132 to varioustube channels, a large expanse of ventricular wall can be covered andhave myocardial channels formed therein.

[0059] Referring now to FIG. 11, a tube-in-a-tube embodiment positioningdevice 180 is illustrated. Positioning device 180 includes an inner PMRcutting probe 182 slidably disposed within an intermediate tube 184which is slidably disposed within an outer tube 186. PMR probe 182 has acutting tip 188 and preferably has radiopaque marker bands 190. Markerbands 190 aid in positioning the PMR probe under fluoroscopy. PMR probe182 is preferably preformed to have an arcuate or bent distal region192.

[0060] Intermediate tube 184 has a channel 194 formed through the tubewall sufficiently large to allow passage of PMR probe 182. In apreferred embodiment, channel 194 is formed in a side tube wall in adistal portion of intermediate tube 184, as illustrated in FIG. 11.Outer tube 186 has an anchoring tip 200 and a slot 196, with slot 196illustrated extending along the longitudinal axis of the outer tube.Slot 196 is sufficiently wide to allow passage of PMR probe 182therethrough. In one embodiment, anchoring tip 200 is formed of a softmaterial and held in place by axial force directed along thelongitudinal axis of device 180. In another embodiment, anchoring tip200 contains a magnetically responsive material and is held in place atleast partially by externally applied magnetic forces. Referring now toFIG. 12, a section of PMR probe 182 is further illustrated, showing onestructure for imparting a preformed arc or bend to the probe. PMR probe182 can include a tube wall 199 having a preform wire 198 embeddedtherein. Preform wire 198 is preferably formed of a shape memorymaterial such as Nitinol, such that the arcuate or bent shape isreformed upon exit from the constraint of intermediate tube 184.

[0061] Referring again to FIG. 11, the wide range of motion possible forcutting tip 188 may be discussed. The radial extent of cutting tip 188,the distance from the center longitudinal axis of outer tube 186, can bevaried by extending PMR probe 182, thereby forcing a longer extent ofexposed probe through intermediate tube channel 194 and through outertube slot 196. As PMR probe 182 has arcuate region 192 in a preferredembodiment, extending PMR probe also changes the longitudinal positionof the cutting tip as more arc is exposed. Sliding intermediate tube 184within outer tube 186 also changes the longitudinal position of cuttingtip 188. Cutting tip 188 is illustrated at a first position A in FIG.11, a second, more distal position B, and a third, still more distalposition C, as intermediate tube 184 is advanced distally within outertube 186. Finally, outer tube 186 can be rotated about its center,longitudinal axis, thereby extending the range of coverage of cuttingtip 188.

[0062] In use, PMR positioning device 180 can be advanced into the leftventricle and anchoring tip 200 forced against some portion of thevermicular wall. Intermediate tube 184 can be slid within outer tube 186to a desired position. Inner PMR probe 182 can be advanced out ofchannel 194 until the desired length of PMR probe is exposed. A desiredposition of cutting tip 188 can be reached by adjusting the length ofPMR probe 182 exposed, the length of intermediate tube 184 advanced intoouter tube 186, and the rotation of outer tube 186. In one method, aseries of arcs of myocardial channels are formed substantiallytransverse to the longitudinal axis of positioning device 180. In thismethod, outer tube 186 is rotated such that cutting tip 188 describes anarc. As each arc is completed, intermediate tube 184 is slid relative toouter tube 186 and a new arc of channels is burned into the ventricularwall.

[0063] Referring now to FIG. 13, an extendable collar embodiment PMRpositioning device 220 is illustrated. Device 220 includes inner PMRprobe 182 disposed within an intermediate tube or sleeve 222 which isslidably disposed within an outer collar 224. Intermediate sleeve 222includes a distal end 240 and has a lumen 242 extending therethrough.Inner PMR probe 182 is preferably slidable within intermediate sleeve222. Device 220 includes an elongate rod 226 having a distal region 228secured to outer collar 224. In a one embodiment, elongate rod 226 iscapable of both pulling and pushing outer collar 224 over intermediatesleeve 222. An elongate anchoring member 230 includes a proximal region236, a distal end 234, a distal anchoring means such as pigtail 234, andcan be slidably and rotatably secured to outer collar 224.

[0064] In one embodiment, elongate rod 226 and anchoring member 230 areboth slidably disposed in a dual lumen tube 227 substantiallycoextensive with intermediate tube 222. Dual lumen tube 227 canterminate the lumen containing elongate rod 226 in a skived portion 229,continuing the tube as a single lumen portion 231. Single lumen portion231 allows elongate rod 226 to freely travel with outer collar 224.Outer collar 224 preferably is slidably disposed over single lumenportion 231.

[0065] Intermediate sleeve 238 and inner PMR probe 182 together have anarcuate or bent bias or preform, as illustrated at 238. In oneembodiment, intermediate sleeve 222 has a preformed shape which can beimparted with an embedded shape wire as illustrated by wire 189 in FIG.12. In another embodiment, PMR probe 182 has an arcuate biassufficiently strong to impart a distal bend to both intermediate sleeve238 and PMR probe 182 when outer collar 224 is retracted. PMR probe 182can include Nitinol or other shape memory material to impart thisarcuate bias. In yet another embodiment, both inner PMR probe andintermediate sleeve 238 have a preformed arcuate or bent distal shape.

[0066] In one embodiment, intermediate tube 222 can be rotated withinouter collar 224. In another embodiment, intermediate tube is restrictedin rotation corresponding ridges and grooves between outer collar 224and intermediate tube 222. In one embodiment, outer collar has internalridges fitting within external grooves in a region of intermediate tube222. Restricting the rotation of intermediate tube 222 within collar 224can aid in causing rotation about anchoring member 230 rather than aboutthe center of outer collar 224.

[0067] In use, outer collar 224 can be extended distally overintermediate sleeve 222, such that collar 224 is proximate intermediatesleeve distal end 240. Inner PMR probe 182 can be preloaded withinintermediate sleeve 222. With outer collar 224 distally extended,arcuate region 238 is substantially restrained and straightened. Device220 can be advanced within the vasculature and into a heart chamber suchas the left ventricle. Elongate anchoring member 230 can be advanceddistally and rotated, thereby rotating pigtail 232 into the ventriclewall and securing anchoring member 230. With intermediate sleeve 222 andPMR cutting tip 188 positioned as indicated at “E” in FIG. 13, theextent of PMR probe exposed can be adjusted by axially sliding PMR probe182 within intermediate sleeve 222. The extent of intermediate sleeveextending distally beyond collar 224 can be adjusted in some embodimentsby advancing or retracting sleeve 222 within collar 224. With PMRcutting tip 188 in position, intermediate sleeve 222 can be rotatedabout anchor member 230 and a circular pattern of myocardial channelscan be burned about the pigtail. In a variant method, possible indevices allowing rotation of intermediate sleeve 222 within outer collar224, intermediate sleeve 222 can be rotated about the center axis ofouter collar 224. With one circle completed, outer collar 224 can beretracted, allowing more of the preformed shape of sleeve 22 and PMRprobe 182 to appear, as illustrated, for example, at “D” in FIG. 13. Ascollar 224 is retracted, PMR probe 182 can be advanced to describecircular paths of increasing radius over the inner ventricle walls. Inthis way, a series of circular paths of myocardial channels about theanchoring point can be formed in the ventricle walls. In one embodiment,elongate member 226 is capable of only retracting collar 224, which,once retracted within the ventricle, cannot be advanced within theventricle. In another embodiment, elongate member 226 is capable of bothadvancing and retracting collar 224 over intermediate sleeve 222. Withthe formation of myocardial channels complete, anchoring member 226 canbe rotated opposite the initial rotation, thereby releasing pigtail 232from the ventricle wall.

[0068]FIG. 14 illustrates an anchorable, cryanoblative PMR treatmentcatheter 320 disposed within a left ventricle 34. The term“cryanoblative”, as used herein, refers to the delivery of coldsufficient to cause tissue death. Similarly numbered elements arediscussed with respect to FIG. 1. Cryanoblative catheter 320 includes aninner star shaft 24 disposed within an outer catheter shaft 22, ananchoring shaft 26 disposed within star shaft 24, and a cryanoblativetreatment tube 330 disposed within catheter shaft 22. Cryanoblativetreatment tube 330 is preferably formed of metal and can include adistal cryanoblative tip 332 and a lumen through which a cold substance,such as liquid nitrogen, is delivered.

[0069] In one embodiment, distal cryanoblative tip 332 includes a distalorifice in communication with the treatment shaft lumen, such thatliquid nitrogen can be delivered through the orifice and to the heartchamber wall. In another embodiment, tube 330 is close ended andinitially under vacuum, allowing liquid nitrogen to be delivered to thetube distal region, causing the tube to become very cold withoutallowing liquid nitrogen to enter the myocardium. The cryanoblative tipcan be inserted into the heart chamber wall, penetrating the wall, andinto the myocardium prior to delivery of liquid nitrogen. The deliveryof liquid nitrogen to the heart chamber wall can cause localized tissuedeath, bringing about the same healing response as laser andradio-frequency current PMR.

[0070] Referring now to FIG. 15, a multi-tube, cryanoblative treatmentprobe 350 is illustrated. Treatment probe 350 includes a plurality ofcryanoblative tubes 354, having distal cryanoblative cutting tips 356,and enclosed within a sheath 52. In one embodiment, tubes 354 are feedfrom a common supply within sheath 52, such that tubes 354 have a shortlength, with most of the length lying distal of the sheath. Probe 350allows a pattern of channels to be formed in the myocardium at the sametime, not requiring repeated repositioning of a single cutting tip suchas cutting tip 332 of FIG. 14. The pattern of cutting tips can becontrolled by utilizing radially outwardly biased cutting tips, whichsplay outward as illustrated in FIG. 15. The amount of splay iscontrolled in one embodiment by allowing the enclosing sheath toretract, allowing the cutting tips to splay further outward. Sheath 52can prevent uncontrolled flopping of distal cutting tips 356, which canpresent a problem when large inter-strand distances arc required, aswith some mechanical cutting tips.

[0071] The coverage of the cutting tips in FIG. 15 allows creation of acomplete pattern of channels in the myocardium without requiringrepositioning of the cutting tips. The resulting myocardial channels canbe formed substantially at the same time, and a similar patterndelivered to an adjacent ventricular wall area soon thereafter. Asdiscussed with respect to FIG. 14, cryanoblative tubes 354 can be formedof metal and be either closed or open ended.

[0072] In a variation of the methods previously described, a radiopaquecontrast media is used to determine the depth of channels formed in themyocardium. The contrast medium is injected or “puffed” into or near thechannel formed in the myocardium. The heart can be visualized underfluoroscopy to determine the depth of the channel formed thus far. Aftervisualization, the channel can be further deepened. The cycle of channelformation, contrast medium puffing, and fluoroscopic visualization canbe repeated until the channel has the desired depth.

[0073] Contrast medium could be injected using a lumen such as the lumenof guide catheter 142 of FIG. 9. A lumen such as the lumen in tube 330of FIG. 14 could also be used to deliver contrast medium. The lumenspreviously discussed with respect to injecting liquid nitrogen could beused to deliver contrast medium.

[0074] In addition to using the device as described herein above to formchannels in the myocardium, the device could be used to form craters inthe myocardium. That is, to form a wound in the myocardium having awidth greater than its depth. The crater can be formed by controllingthe depth of insertion of, for example, a radiofrequency device and/orcontrolling the power delivered to the distal tip of the device suchthat a crater is formed. Those skilled in the art can also appreciatethat mechanical devices, laser devices or the like could be used to formcraters.

[0075] In use, the above methods and devices can be used to form apattern of channels leading from healthy myocardial tissue tohibernating tissue. This can operate by multiple mechanisms to supplyhibernating tissue with an increased blood supply. First, channels inthe myocardium can perfuse tissue directly from the ventricle, throughthe patent channel formed by the cutting tip. Second, the channelsformed by the cutting tip can become newly vascularized by operation ofa healing response to the channel injury. The new blood vessels therebyincrease further the supply of hibernating tissue by ventricular blood.Third, the series of newly formed vessels caused by the healing responsecan form interconnections or anastomoses between the series of injuredareas, forming a network of blood vessels, which, by connecting withhealthy area vessels, can be supplied by blood originating from coronaryarteries in addition to blood supplied directly by the ventricle.

[0076]FIG. 16 shows yet another embodiment of the present invention inthe form of catheter assembly 400. Here only the distal end of catheterassembly 400 is shown disposed within the left ventricle of a patient'sheart. Those skilled in the art will appreciate the variousconfigurations possible for the proximal end of the catheter in view ofthe description of the distal end which follows. Catheter assembly 400includes an elongate guide wire 402 having a distal end and a proximalend. A collapsible loop 404 is hingably connected to the distal end ofguide wire 402. A retraction member 406 is hingably connected to loop404 opposite the connection to guide wire 402. Therapeutic catheter 408,which has a lumen extending therethrough, is shown advanced over guidewire 402. Catheter 408 has a distal end and a proximal end, andproximate the distal end of catheter 408 is a therapeutic member 410.Therapeutic member 410 can be an elongate electrode having a ball tip.In a preferred embodiment, a conductor extends through catheter 408 todeliver RF energy to electrode 410. Electrode 410 can be hingablyconnected to catheter 408 such that catheter assembly 400 can beadvanced through a guide catheter 412.

[0077] The materials to be used, and the methods of fabrication, to makecatheter assembly 400 will be known to one skilled in the art in view ofthe uses to which catheter assembly 400 are put. As shown in FIG. 16,loop 404 is disposed in a first collapsed position A. In collapsedposition A, loop 404 is advancable to left ventricle 34 of heart 35 by apercutaneous route through the aorta. FIG. 17 shows loop 404 in a secondposition B deployed within left ventricle 34. When loop 404 is in secondposition B, a portion of guide wire 402 lies near and approximatelyparallel to left ventricle wall 36, while a portion of loop 404 abutsthe opposite wall. In this position, catheter 408 can be advanced asshown by the arrow along guide wire 402. As catheter 408 is advanced,electrode 410 can be energized repeatedly to form holes or channels 442in wall 36. A further series of holes 442 can be formed by rotating wire402 and loop 404 as shown by the arrows adjacent loop 404.

[0078] In order to move loop 404 between first position A and secondposition B, guide wire 402 should be relatively rigid in comparison toloop 404 and actuator member 406. With that configuration, actuator 406can be pulled proximately to move loop 404 from second position B tofirst position A. In turn, actuator member 406 can be moved distally todeploy loop 404.

[0079]FIG. 18 is a view of the distal end of catheter 408 showing analternate therapeutic device. In particular, a hypodermic needle 414 isshown extending from distal end 408. Hypodermic needle 414 is preferablyhingable connected to catheter 408 such that it can be advanced andwithdrawn through a guide catheter. If catheter 408 includes an infusionlumen, contrast media, growth factor or other drug can be delivered towall 36 through needle 414.

[0080]FIG. 19 is a view of the distal end of catheter 408 showing yetanother therapeutic device disposed thereon. In particular, an electrode416 is shown which has a length greater than the distance which itextends transversely from catheter 408. Such an electrode can be used toform a crater 444 having a width greater than its depth.

[0081]FIG. 20 is a view of the distal end of catheter 408 showinganother therapeutic device disclosed thereon. In FIG. 20 an abrasiveburr 418 is shown extending transversely from catheter 408. Whenrotated, burr 14 can form a crater 444. In both FIGS. 19 and 20,electrode 416 and burr 418 are shown spaced from heart wall 36. Whilecreating craters 444, it is understood that loop 404 will be deployed insecond position B such that electrode 416 and burr 418 will be incontact with heart wall 36.

[0082] It can be appreciated that each of the devices disclosed hereincan be bi-polar as well as mono-polar. To make a bi-polar configuration,a ground electrode would need to be disposed on the device proximate theelectrode(s) shown.

[0083] Numerous characteristics and advantages of the invention coveredby this document have been set forth in the foregoing description. Itwill be understood, however, that this disclosure is, in many respects,only illustrative. Changes may be made in details, particularly inmatters of shape, size, and arrangement of parts without exceeding thescope of the invention. The inventions's scope is, of course, defined inthe language in which the appended claims are expressed.

What is claimed is:
 1. A method for increasing blood perfusion to heartmuscle wall by forming a plurality of channels in the myocardiumcomprising the steps: marking a first location within said heart musclewall by securing a radiopaque marker to said heart muscle wall;positioning a radiopaque, channel forming tip at a second location witha chamber of said heart; viewing said first and second locationsfluoroscopically; adjusting said second location relative to said firstposition; and forming said channel in said myocardium at said secondlocation using said treatment tip.
 2. A method for increasing bloodperfusion as recited in claim 1, wherein said radiopaque marker issecured to said heart muscle with a marker selected from the group offasteners consisting of hooks, barbs, bent members and curled members.3. A method for increasing blood perfusion as recited in claim 1,wherein said radiopaque marker is secured to said heart muscleadhesively.
 4. A method for increasing blood perfusion as recited inclaim 1, wherein said radiopaque marker is secured to said heart muscleby injecting said marker within said wall.
 5. A method for increasingblood perfusion as recited in claim 1, wherein said fluoroscopicvisualization is accomplished on a computer generated display.
 6. Amethod for increasing blood perfusion as recited in claim 4, whereinsaid radiopaque marker is a radiopaque dye.
 7. A method for increasingblood perfusion as recited in claim 4, wherein said radiopaque marker isa metal.
 8. A method for increasing blood availability to heart musclemyocardium having healthy, hibernating, and infarcted dead tissuecomprising: providing a treatment tip having the capability of forming achannel in said myocardium from within said heart; selecting a firstlocation in said healthy tissue; selecting a second location in saidhibernating tissue; and forming a plurality of channels utilizing saidtreatment tip in said myocardium in a pattern extending from said firstlocation to said second location.
 9. A method as recited in claim 8,wherein said channels are formed substantially sequentially.
 10. Amethod as recited in claim 8, wherein said treatment tip includes aplurality of cutting tips and said channels are formed substantially atthe same time.
 11. A method as recited in claim 8, wherein said patternis substantially linear between said first and second locations.
 12. Amethod as recited in claim 8, wherein said pattern is substantially acircular cluster including said first and second locations.
 13. A methodas recited in claim 8, wherein said pattern is substantially an arraybetween said first and second locations.
 14. A method as recited inclaim 8, wherein said treatment tip is selected from the groupconsisting of mechanical cutting probes, laser cutting probes and radiofrequency cutting probes.
 15. A method as recited in claim 8, furthercomprising injecting radiopaque material into said channels, such thatthe positions of said channels are fluoroscopically viewable.
 16. Amethod as recited in claim 8, wherein said treatment tip includes amechanical cutting tip having a lumen therethrough, further comprisinginjecting radiopaque material through said lumen into said channels,such that the position of said channels are fluoroscopically viewable.17. A method for increasing blood availability to heart muscle byforming a plurality of channels in the myocardium comprising the steps:providing a myocardial channel forming device having an anchoringmember, at least one treatment member, and means for rotating saidtreatment member about said anchoring member, wherein said treatmentmember includes means for forming a channel in said myocardium;attaching said anchoring member to a first position in said myocardium;rotating said treatment member to a desired rotational angle relative tosaid anchor; and forming a channel in said myocardium.
 18. A method forincreasing blood availability to heart muscle as recited in claim 17,wherein said channel forming device has a longitudinal axis extendingthrough said anchoring member, said treatment member has a distal tipdisplaced a radial distance from said longitudinal axis, said channelforming device includes means for controlling said treatment memberdistal tip radial distance, further comprising setting said treatmentmember radial distance.
 19. A method for increasing blood availabilityto heart muscle as recited in claim 18, wherein said means forcontrolling said rotational angle includes an elongate tubular memberhaving a lumen and a wall, wherein said anchoring member is disposedwithin said lumen and said treatment probe is attached to said tubewall, such that said treatment member rotational angle can be controlledby rotating said elongate tube about said anchoring member.
 20. A methodfor increasing blood availability to heart muscle as recited in claim19, wherein said treatment member is slidably attached to said tubularwall, said treatment member distal tip is bent away from said anchoringmember and has a longitudinal displacement relative to said anchoringmember, such that the longitudinal and radial displacement of saidtreatment member distal tip can be adjusted by slidably adjusting saidtreatment member distal tip longitudinal displacement within said tube.21. A method for increasing blood availability to heart muscle asrecited in claim 18, wherein said device includes an elongate tubularmember having a lumen and a wall, wherein said anchoring member and saidtreatment probe are disposed within said lumen, such that said treatmentmember rotational angle can be controlled by rotating said treatmentmember.
 22. A device for creating a plurality of myocardial channelscomprising: an elongate tube having a distal port; an anchoring memberslidably disposed within said elongate tube, said anchoring memberhaving a pointed distal end extending from said elongate tube distalport, said pointed distal end adapted to penetrate into said myocardium;a treatment member slidably disposed within said elongate tube, saidtreatment member having an arcuate distal region having a cutting tipthereon, said arcuate distal region being biased to increase in radiuswhen not constrained within said tube, such that said distally extendingsaid elongate tube causes said treatment member distal end to decreasein radial distance from said anchor member and proximally retractingsaid elongate tube causes said treatment member distal end to increasein radial distance from said anchor member.
 23. A device for creating aplurality of myocardial channels as recited in claim 22, wherein saidtreatment member is disposed within a treatment member lumen in saidelongate tube distinct from said anchoring member lumen, such that saidtreatment member can be rotated about said anchoring member by rotatingsaid elongate tube about said anchoring member.
 24. A device forcreating a plurality of myocardial channels as recited in claim 23,further comprising means for restricting said rotation of said treatmentmember relative to said anchoring member to a finite set of rotationalpositions.
 25. A device for creating a plurality of myocardial channelscomprising: an elongate tube having a distal port and a longitudinalaxis; a plurality of wires disposed within said elongate tube, saidwires having distal tips deployed about said longitudinal axis, suchthat a pattern of wire distal tips is formed distal of said tube distalport; a radio-frequency energy source connected to said wires, saidenergy source capable of creating energy at said wire distal tipssufficient to burn channels in said myocardium, such that a pattern ofmyocardial channels can be created by supplying said radio-frequencyenergy to said wires.
 26. A method as recited in claim 8, furtherproviding at least one external magnet, wherein said treatment tip has adistal region responsive to magnetic forces, such that said treatmenttip is at least partially guided into a cutting position utilizing saidmagnetically responsive distal region and said external magnet.
 27. Adevice for creating a myocardial channel comprising: a catheter having amagnetically responsive distal region and a distal cutting tip, suchthat said cutting tip can be at least partially guided into a cuttingposition utilizing said magnetically responsive distal region respondingto an external magnetic force.
 28. A device for creating a myocardialchannel as recited in claim 27, wherein said catheter magneticallyresponsive distal region can be pulled by said external magnetic force.29. A device for lessening the movement of a beating heart wall portioncomprising: a catheter having a magnetically responsive distal region,said catheter being adapted to be received within a coronary artery,such that said catheter magnetically responsive distal region can haveforce exerted thereon by an external magnet while said catheter isreceived within said coronary artery.
 30. A method for lessening themovement of a beating heart wall portion comprising the steps: providinga catheter having a magnetically responsive distal region; providing atleast one external magnet; inserting said catheter distal region into acoronary vessel near said heart wall portion; and positioning saidexternal magnet near said catheter distal region, such that saidexternal magnet exerts force on said magnetically responsive catheterdistal region within said heart wall portion, presenting resistance tosaid heart wall movement.
 31. A device for lessening the movement of abeating heart wall portion comprising: a catheter having a magneticallyresponsive distal region, said catheter being adapted to be receivedwithin a coronary artery, such that said catheter magneticallyresponsive distal region can have force exerted thereon by an externalmagnet while said catheter is received within said coronary artery. 32.A device for lessening said beating heart wall portion movement asrecited in claim 31, wherein said magnetically responsive distal regioncan be pulled by said external magnet.
 33. A method for increasing bloodavailability to heart muscle as recited in claim 17, further providingat least one external magnet, wherein said anchoring member includes amagnetically responsive distal region and said attaching step includesexerting magnetic force by said external magnet on said anchor membermagnetically responsive distal region, such that said anchor memberdistal region is forced toward said myocardium.
 34. A device forcreating a plurality of myocardial channels comprising: an elongate tubehaving a distal port; an anchoring member slidably disposed within saidelongate tube, said anchoring member having a magnetically responsivedistal region extending from said elongate tube distal port, said distalregion adapted to contact a heart wall region near said myocardium, suchthat said anchoring member can be forced into said heart wall region inresponse to an external magnetic force; and a treatment member slidablydisposed within said elongate tube, said treatment member having anarcuate distal region having a cutting tip thereon, said arcuate distalregion being biased to increase in radius when not constrained withinsaid tube, such that said distally extending said elongate tube causessaid treatment member distal end to decrease in radial distance fromsaid anchor member and proximally retracting said elongate tube causessaid treatment member distal end to increase in radial distance fromsaid anchor member.
 35. A device for creating a plurality of myocardialchannels as recited in claim 34, wherein said treatment member isdisposed within a treatment member lumen in said elongate tube distinctfrom said anchoring member lumen, such that said treatment member can berotated about said anchoring member by rotating said elongate tube aboutsaid anchoring member.
 36. A device for guiding a PMR cutting wiredistal region to a plurality of heart chamber wall sites comprising: anelongate outer tube having a tubular wall and a distal region, saiddistal region wall having a plurality of channels therethrough; andmeans for stabilizing the position of said outer tube distal regionwithin said heart chamber, such that said PMR cutting wire distal regioncan be advanced through said outer tube distal region wall channels tosaid heart chamber wall sites.
 37. A device for guiding a PMR cuttingwire as recited in claim 36 wherein said means for stabilizing saidouter tube position includes a suction orifice disposed in said outertube distal region, said orifice being adapted to make contact with saidheart chamber wall, said orifice being in fluid communication with avacuum lumen substantially co-extensive with said outer tube.
 38. Adevice for guiding a PMR cutting wire as recited in claim 36 whereinsaid means for stabilizing said outer tube position includes amagnetically responsive portion of said outer tube distal region, suchthat an externally applied magnetic field can exert a force upon saidouter tube distal region.
 39. A device for creating a plurality ofmyocardial channels in a heart chamber wall comprising: an elongateouter tube having a tubular wall and a distal region, said distal regionwall having a plurality of channels therethrough; means for stabilizingthe position of said outer tube distal region within said heart chamber;and a PMR cutting wire having a distal region disposed within said outertube, such that said PMR cutting wire distal region can be advancedthrough said outer tube distal region wall channels to said heartchamber wall.
 40. A device as recited in claim 39, further comprising aguide tube disposed about said PMR cutting wire and disposed within saidouter tube.
 41. A device as recited in claim 39, wherein said PMRcutting wire distal region has a distal tip and an arcuate biasproximate said distal tip such that said distal region is predisposed toextend through said outer tube channels when said distal tip is passedover said channels.
 42. A device as recited in claim 39, wherein saidmeans for stabilizing said outer tube position includes a suctionorifice disposed in said outer tube distal region, said orifice beingadapted to make contact with said heart chamber wall, said orifice beingin fluid communication with a vacuum lumen substantially co-extensivewith said outer tube.
 43. A device as recited in claim 39, wherein saidmeans for stabilizing said outer tube position includes a magneticallyresponsive portion of said outer tube distal region, such that anexternally applied magnetic field can exert a force upon said outer tubedistal region.
 44. A device as recited in claim 39, further comprisingan elongate shape member said outer tube and secured to said outer tubewall over at least said outer tube distal region, said shape memberhaving a preformed shape such that said outer tube distal region isbiased to assume said shape member preformed shape.
 45. A device forcreating a plurality of myocardial channels in a heart chamber wallcomprising: an elongate outer tube having a longitudinal axis, aproximal end, a distal end, a tubular wall and a distal region, saiddistal region wall having an elongate slot therethrough, said slothaving a length; an elongate intermediate tube disposed within saidouter tube, said intermediate tube having a wall, a distal region, and achannel in said distal region wall; and an elongate inner PMR cuttingprobe disposed within said intermediate tube and adapted to extendthrough said intermediate tube channel such that a distal length of saidPMR cutting probe extends outside of said intermediate and outer tubes,wherein said PMR cutting probe extends at a longitudinal positionrelative to said outer tube, said outer tube slot having a proximalportion and a distal portion, said intermediate tube being slidablewithin said outer tube, said inner PMR cutting probe being slidablewithin said intermediate tube, such that said PMR probe extended distallength can be varied by sliding said inner PMR probe within saidintermediate tube and through said intermediate tube channel, such thatsaid PMR probe longitudinal position can be varied by sliding saidintermediate tube within said slot, such that said PMR probe can berotated by rotating said outer tube.
 46. A device for creating aplurality of myocardial channels in a heart chamber wall comprising: anelongate rod having a proximal region and a distal region, said roddistal region secured to an outer collar; an intermediate tube slidablyreceived within said collar; an inner PMR cutting probe slidablyreceived within said intermediate tube; an elongate anchoring memberhaving a proximal region and a distal end, said anchoring member beingslidably secured to said collar, said anchoring member having anchoringmeans disposed proximate said anchoring member distal end, saidintermediate tube distal region containing said inner PMR probe togetherhaving a distal region arcuate bias, such that extending said outercollar distally over said intermediate tube straightens out saidintermediate tube and retracting said outer collar proximally over saidintermediate tube allows said arcuate shape to return, such that slidingsaid intermediate tube relative to said anchoring member moves saidcontained inner PMR probe distal end relative to said anchoring means.47. A device as recited in claim 46, wherein said anchoring meansincludes a pigtail adapted to screw into said heart chamber wall andsaid anchoring member is rotatable relative to said collar, such thatsaid pigtail can be rotated by rotating said anchoring member.
 48. Adevice as recited in claim 46, wherein said anchoring means includes amagnetically responsive portion, such that an externally appliedmagnetic field can exert a force upon said anchoring member distalregion.
 49. A method for increasing blood availability to heart muscleby causing localized tissue death at a plurality of sites in themyocardium comprising the steps: providing a myocardial localized tissuekilling device having an anchoring member, at least one treatmentmember, and means for rotating said treatment member about saidanchoring member, wherein said treatment member includes means forkilling tissue in said myocardium; attaching said anchoring member to afirst position in said myocardium; rotating said treatment member to adesired rotational angle relative to said anchor; and causing tissuedeath in said myocardium.
 50. A method as recited in claim 49, whereinsaid treatment member includes a tube having a lumen therethrough andsaid causing step includes delivering a cold substance through saidlumen.
 51. A method as recited in claim 50, wherein said cold substanceis liquid nitrogen.
 52. A method as recited in claim 50, wherein saidcold treatment member has a distal orifice in fluid communication withsaid treatment member lumen.
 53. A device for killing tissue at aplurality of myocardial sites comprising: an elongate tube having adistal port; an anchoring member slidably disposed within said elongatetube, said anchoring member having a pointed distal end extending fromsaid elongate tube distal port, said pointed distal end adapted topenetrate into said myocardium; a treatment member capable of causinglocalized tissue death slidably disposed within said elongate tube, saidtreatment member having an arcuate distal region having a treatment tipthereon, said arcuate distal region being biased to increase in radiuswhen not constrained within said tube, such that said distally extendingsaid elongate tube causes said treatment member distal end to decreasein radial distance from said anchor member and proximally retractingsaid elongate tube causes said treatment member distal end to increasein radial distance from said anchor member, wherein said treatmentmember is disposed within a treatment member lumen in said elongate tubedistinct from said anchoring member lumen, such that said treatmentmember can be rotated about said anchoring member by rotating saidelongate tube about said anchoring member.
 54. A device as recited inclaim 53, wherein said treatment member includes a lumen adapted todeliver liquid nitrogen to said treatment member distal end.
 55. Adevice as recited in claim 54, wherein said treatment member distal endincludes an orifice in communication with said treatment member lumen.56. A device for causing localized tissue death at a plurality ofmyocardial sites comprising: an elongate tube having a distal port and alongitudinal axis; a plurality of treatment tubes disposed within saidelongate tube, said treatment tubes having distal tips deployed aboutsaid longitudinal axis, such that a pattern of treatment tube distaltips is formed distal of said tube distal port; a cryogenic substancesource connected to said treatment tubes, said cryogenic source capableof causing cold at said treatment tube distal tips sufficient to causetissue death in said myocardium, such that a pattern of localizedmyocardial tissue death can be created by supplying said cryogenicsubstance to said treatment tubes.
 57. A device as recited in claim 56,wherein said cryogenic substance is liquid nitrogen.
 58. A catheterassembly, comprising: a guidewire having a proximal end and a distalend; an expandable member disposed at the distal end of the guide wire,the expandable member being moveable between a first position and asecond position, in the first position, the member being collapsed tomove through a lumen of a guide catheter, in a second position, theexpandable member having a transverse diameter with respect to thelength of the guidewire greater than the transverse diameter of theguide catheter lumen; an elongate catheter having a proximal end and adistal end, the catheter defining an elongate lumen, and the guidewirebeing disposed in the lumen; and a therapeutic device connected to thecatheter and disposed proximate the distal end of the catheter.
 59. Thecatheter assembly in accordance with claim 58, wherein the expandablemember includes a wire loop.
 60. The catheter assembly in accordancewith claim 58, wherein the therapeutic device includes a needle.
 61. Thecatheter assembly in accordance with claim 60, wherein the needleincludes a hypotube.
 62. The catheter assembly in accordance with claim58, wherein the therapeutic device includes an electrode.
 63. Thecatheter assembly in accordance with claim 62, wherein the electrodeextends transversely from the catheter a length greater than width ofthe electrode.
 64. The catheter assembly in accordance with claim 58,wherein the therapeutic device includes a rotatable burr.
 65. A methodof performing PMR, comprising the steps of: providing a catheterassembly including a guidewire having a distal end expandable member,and a catheter advancable over the guidewire, the catheter having adistal end and a therapeutic device disposed proximate the distal end;advancing the expandable member into a chamber of a patient's heart;expanding the expandable member such that a length of the guidewireproximate the distal end of the guidewire is disposed proximate a wallof the chamber; advancing the catheter over the guidewire such that thetherapeutic device is adjacent the wall; and actuating the therapeuticdevice to deliver therapy to the heart wall.
 66. The method inaccordance with claim 65, further comprising the step of incrementallyadvancing the therapeutic device along the heart wall and delivering thetherapy to the heart wall intermittently as the device is incrementallyadvanced.
 67. The method in accordance with claim 65, further comprisingthe step of rotating the guidewire to disposed the catheter proximateanother portion of the wall.